only happens after a long ride... Does it when driving but it is like a hiccup or hesitation (only at steady speed).. give it some gas and it stops. i have replace the map sensor, throttle position sensor, fuel filter, ignition coil, ignition module, air filter, the idol sensor, distributor cap, Spark plugs, and spark plug wires as well.... nothing has helped or fixed it is a TBI 2.5L 1990
You cant just replace a sensor on the pre 91 renix controller(87-90YJ). You need to set the refrence for the sensor after replacing it. There are 4 adjustments Wide open throttle switch(WOT), the throttle position sensor(TPS), Idle Speed Adjustment Motor(ISA), and the fuel pressure on the throttle body. If you replace any component in the system you need to reset the refrence using the procedure in the service manual. You need to look at the the O2 sensor and fixing any exhaust leak before the O2 sensor on the exhaust manifold. The O2 is the prime controller for fuel air after it goes into closed loop after warm up. You might want to clean up the throttlebody while you are at it too.
If you download the FSM and you are not a member of dropbox, please PM Ninjakid and join under him. It gives him more space to store and it is a real generous thing to get the manual for free! http://jeepspace.jeepforum.com/ninjakid
Best for you is you are about 100 mile from the Ultimate YJ guy here on the forum Mean Max. Dont let the name fool you he is anything but mean. He has a shop in Stuart and if you really cant do it I cant recommend strong enough taking your Jeep to him. PM him: http://jeepspace.jeepforum.com/Mean%20Max
The renix controllers require a little more effort when you replace things and in troubleshooting.Timing chain makes sense too. You can check that by pulling the distributor cap. Use a wrench on the crank shaft nut on the damper and move it until you see the rotor start to turn. Stop and move it the other direction. The difference you turn is the amount of slop in the chain. There should be no more then 1/4" movement without the distributor moving.
You still need to do the adjustments though. It is critical. Also like the OBDI systems you can look for differences cold/hot to see if the O2 or CTS are causing problems when it goes from open loop to closed loop.
So i put the o2 in 2 months ago and if fixed to problem but now in to doing all most the same thing after driving in for 15-20 min it bogs down on me. i put the throttle all the way down to give it gas and it does not go any where.
the filter is is good as well....
could the cat be the problem. could it be making to much back pressure the it is boging it down? if so i can just pull the cat out and run a pipe with a muffler right?